Positive:
* It is very small and doesn't take space in the car.
* It works well to charge several mobile phones
Neutral:
* Some people mentioned that it was not long enough to make good contact in some cars. In my car, it could still be 5mm shorter and it would still make good contact. In fact I would prefer it 5mm shorter.
Negative:
* There's no indication of what's the max current that this device can deliver. Is it the standard 0.5A or up to 1A that is required by some special devices powered by USB? (In the Amazon image for this item I had seen 1A)
* Whenever I use it to power a Garmin GPS, the GPS starts in the USB storage connection mode, like when I connect it to a PC. After a while, the GPS resets automatically and then works normally as intended.